Guy Williams, who was famous for playing Walt Disney's Zorro, was to have replaced Pernell Roberts, in the character of Will Cartwright, Ben's lost nephew. However, with the uncertain fate of Roberts' decision to stay or leave, and coupled with resentment from the cast, mainly Michael Landon, who didn't think he was necessary, forced Williams to leave and pursue his career, as with Lost In Space, which was really beneath him.
He moved to Buenos Aires, Argentina in 1978, after visiting there for several years, and passed away in late April of 1989. He is fondly remembered by his fans today as Zorro, still.